Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Cat Health & Care

How to Tell if Your Cat Is Underweight: Vet-Reviewed Signs to Look For

By Kerry-Ann Kerr · Reviewed & fact-checked by Dr. Lorna WhittemoreVet Approved
Dr. Lorna Whittemore
Reviewed & Fact-Checked byDr. Lorna WhittemoreMRCVS (Veterinarian)
Lorna is a vet based in Cape Town, South Africa. originally from Scotland. Lorna loves to travel and has lived, studied, and worked on three continents. Lorna has 20 years of experience in small animal medicine and surgery, both in the charity and private sector, plus a further qualification in feline medicine.View authorThe information is current and up-to-date in accordance with the latest veterinarian research. Read about our vets
Share
Skinny cat

Feeding your cat a healthy diet that will ensure they stay at an appropriate weight is crucial. However, you might be doing exactly that, but your cat is still shedding the pounds. If you suspect your cat is losing weight despite no changes in your routine, consult your vet immediately. There are some things you can do at home first to either confirm your suspicions or alleviate your fears.

We’ll go through those together, what signs to look for, and what may be causing the sudden drop in weight.

divider single cat paw oct 2024

How to Tell Your Cat Is Underweight

Cat Body Condition Score Healthy Weight
You are free to use this image but we do require you to link back to Catster.com for credit

Figuring out if your cat is underweight can be a challenge, but don’t worry; we’re not asking you to try and wrestle your kitty onto a set of scales. There are two things you can do at home.

The first is the Body Condition Score, which vets use to evaluate a pet’s weight and is like BMI for humans. You can find a chart at your vet or online from organizations like the American Animal Hospital Association and the World Small Animal Veterinary Community.

The second thing you can do is the Hand Test. Feel your cat’s ribs, which you’ll find behind their front legs. Their weight is perfect if they feel like the back of your hand. If their ribs resemble your knuckles, your cat is skinny. If their ribs feel like your palm, they’re potentially overweight.

These at-home tests are a way to determine whether or not your next stop is the vet. If you can feel a pronounced ribcage or spine, a vet can do a more thorough exam and determine the cause of the weight loss.

Another helpful tool is calculating the amount of calories your cat needs, our calculator below can help you determine how much food your cat needs based on things like their current BCS, age, weight and activity level.

Cat Calorie Calculator

Weight
Reproduction

The exact amount of calories an individual animal needs to maintain a healthy weight is variable and influenced by many factors including genetics, age, breed, and activity level. This tool is meant to be used only as a guideline for healthy individuals and does not substitute veterinary advice

Causes of Weight Loss

Image Credit by: Aun25, Shutterstock

There are two main reasons for a skinny cat: they’re using more energy than they’re taking in or aren’t eating enough.

A cat can lose its appetite for several reasons, including stress, nausea, dental disease, organ dysfunction, or other reasons. Weight loss can be age-related, as a decline in organ function and muscle mass is more common in senior cats.

Where Do I Start?

Monitor your cat’s eating, and ensure they finish their food. Does your cat seem hungry after it’s eaten? Different food brands have feeding requirements based on age, size, and activity level, so double-check that you’re following these correctly.

If you have more than one feline, ensure one cat isn’t hogging all of the food and leaving the other with a rumbly tummy. Separating cats into different rooms to eat is a solution if your cats are becoming a little competitive during mealtimes.

Signs of Weight Loss

While a skinny cat doesn’t necessarily mean a medical emergency, one that stops eating must be examined by a vet.

Cats that don’t eat for days can develop fatty liver syndrome, a life-threatening condition also known as hepatic lipidosis. Arguably, rapid weight loss is easier to spot than gradual weight loss, so you’re not just looking out for a cat that stops eating altogether. These are signs to look out for if you suspect your cat is losing weight:

  • Bad breath
  • Diarrhea
  • Drooling
  • Eating more/less
  • Lethargy
  • Loss of muscle, especially around the back legs and spine
  • Peeing or drinking more than usual
  • Poor coat condition
  • Very vocal/more demanding than usual
  • Vomiting

Seek veterinary advice if you’re concerned about your cat’s weight and well being.

divider 3 paws

3 Ways to Help Your Cat Gain Weight

Once your vet has ruled out any underlying health conditions, you can try these tips to help your cat get back to a healthy weight.

1. Change Up Your Routine

Image Credit by: Crazy nook, Shutterstock

It could be that your cat just needs more food. You could add more meals, or maybe your cat would like the option of choosing when to eat. You could allow your cat to “graze” instead of eating larger meals throughout the day.


2. Change Their Food

Has your cat started a new diet recently? Maybe it doesn’t agree with them. Try a different brand or flavor or change protein sources, which would also rule out if food sensitivities or allergies are what’s causing your cat’s weight problem. Your vet will be able to help with choosing a diet.

If your cat eats kibble, try adding water or unsalted chicken broth to their food to make it more appealing. Heating food in the microwave can also make it smell better, which may entice a curious cat to eat. If you change your pet’s diet, consult your vet for advice.


3. The Environment

As we already mentioned, if you have multiple cats, try feeding them in separate rooms in case one cat is stopping another from eating everything it wants.

Examine the room with the food bowls and see if anything is preventing your cat from enjoying its meal. Maybe their bowl is next to something loud, like a fan or a furnace. Try changing where you feed them to see if this solves the problem.

divider cat paws 2 oct 2024

Final Thoughts

If you suspect your cat is underweight, you must contact your vet as soon as possible. The weight loss could be related to the environment, cat food, or a health condition. Whatever it is, you can devise a plan with your vet on how to tackle this problem together and get your cat back to a healthier weight!

Sources

Featured Image Credit by: Poto69, Shutterstock

The Catster Newsletter

Expert cat care, straight to your inbox

News, insights, and useful advice, delivered to you.

No spam — unsubscribe anytime.

By signing up, you agree to our Terms & Conditions and Privacy & Cookies Policy.

Click a star to rate. You can leave written feedback afterwards. (We read all feedback.)

Kerry-Ann Kerr
Authored by

Kerry-Ann Kerr

Leave a Reply

You're very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let's have a positive and constructive conversation.

My Cat Is So Skinny I Can Feel Their Bones: Should I Worry? Vet-Reviewed Advice

My Cat Is So Skinny I Can Feel Their Bones: Should I Worry? Vet-Reviewed Advice

Many of us are so used to seeing large and overweight cats that it can be surprising to see a cat that is thin. That means it can be difficult for many people…

Brooke Billingsley
By Brooke Billingsley ·
How Do I Get My Cat to Gain Weight? Our Vet Answers With Infographic

How Do I Get My Cat to Gain Weight? Our Vet Answers With Infographic

Monitoring your cat’s weight is a great way to get a hint about how well they are eating and if their overall health is on track. Kittens should steadily gain…

Dr. Joanna Woodnutt BVM BVS
By Dr. Joanna Woodnutt BVM BVS ·
How to Tell if a Cat Is Hungry: Vet-Approved Facts & Nutrition Guide

How to Tell if a Cat Is Hungry: Vet-Approved Facts & Nutrition Guide

We’ve all been there. You’re relaxing on the couch or at your desk. Suddenly, you hear the meows. You try to ignore them because, according to the clock, it’s…

Christian Adams
By Christian Adams ·
Why Is My Cat Losing Weight? 10 Possible Reasons (Vet Answer)

Why Is My Cat Losing Weight? 10 Possible Reasons (Vet Answer)

If you have noticed that your cat is looking a little leaner than normal recently, then you might also be wondering why this is. Many older cats, in particular…

Dr. Rebecca MacMillan
By Dr. Rebecca MacMillan ·

What to Feed an Old Cat to Gain Weight: 5 Vet-Approved Tips

While to a certain extent, it’s normal for a cat to lose weight during their senior years, it’s also essential for you, as a pet parent, to do everything that…

Patricia Dickson
By Patricia Dickson ·
What to Feed an Old Cat to Gain Weight: 5 Vet-Approved Tips

How Long Can Cats Go Without Food? Vet-Verified Dangers & Tips

Cats are often hungry little monsters devouring their food rapidly. Conversely, they may be picky eaters that refuse to eat anything but their favorites! In ei…

Christian Adams
By Christian Adams ·
How Long Can Cats Go Without Food? Vet-Verified Dangers & Tips

How Much Should My Cat Weigh? Vet-Approved Chart & Infographic

Cats are one of America's favorite pets, but as more of them spend their lives indoors, they are also putting on more weight. Obesity can lead to several healt…

Christian Adams
By Christian Adams ·
How Much Should My Cat Weigh? Vet-Approved Chart & Infographic

Cat Body Condition Score: What Is It & How To Work It Out

The Body Condition Score (BCS) is a quantitative method for evaluating body fat. Think of it as the animal equivalent of the Body Mass Index (BMI) for humans.…

Chantelle Fowler
By Chantelle Fowler ·
Cat Body Condition Score: What Is It & How To Work It Out

How to Weigh Your Cat: 5 Vet-Approved Steps

Though it may not be considered a necessary part of caring for cats, there are significant benefits to weighing your cat. Since cats can’t use words to tell us…

Jessica Kim
By Jessica Kim ·
How to Weigh Your Cat: 5 Vet-Approved Steps

How to Make a Hyperthyroid Cat Gain Weight: 4 Vet-Reviewed Ways to Help

Cats with hyperthyroidism can live healthier lives if their condition is managed. Since one major sign of hyperthyroidism is weight loss, cat owners may wonder…

Jessica Rossetti
By Jessica Rossetti ·
How to Make a Hyperthyroid Cat Gain Weight: 4 Vet-Reviewed Ways to Help

10 Ways to Monitor Your Cat’s Health at Home: Vet Verified

Thanks to their instincts for self-preservation, cats are masters at hiding signs of illness or injuries. If you want to catch medical problems early, you must…

Elizabeth Gray
By Elizabeth Gray ·
10 Ways to Monitor Your Cat’s Health at Home: Vet Verified

How to Tell If Your Cat Is Overweight: 4 Vet-Reviewed Signs to Look For

Do you suspect that your cat is on the chunky side? If so, are you wondering how to tell or what signs to look for? Obesity is a common problem with domesticat…

Rachel Giordano
By Rachel Giordano ·
How to Tell If Your Cat Is Overweight: 4 Vet-Reviewed Signs to Look For

Love Cats? So Do We! Join the Catster Community

Stay informed with expert cat care insights delivered straight to your inbox! Discover professional guidance on feline behavior, feeding tips, trusted product picks, and much more.

You may opt-out at any time. View our Privacy Policy for more information.

The Catster site on a phone